Optical imaging lens

ABSTRACT

An optical imaging lens includes a first lens element to a sixth lens element from an object side to an image side along an optical axis. The first lens element has negative refracting power, the second lens element has negative refracting power and a periphery region of the object-side surface of the second lens element is convex, a periphery region of the image-side surface of the third lens element is concave, a periphery region of the object-side surface of the fifth lens element is concave and a periphery region of the image-side surface of the fifth lens element is concave. Lens elements included by the optical imaging lens are only six lens elements described above. AAG is a sum of five air gaps from the first lens element to the sixth lens element along the optical axis, and EFL is an effective focal length to satisfy AAG/EFL≤2.700.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention generally relates to an optical imaging lens.Specifically speaking, the present invention is directed to an opticalimaging lens for use in portable electronic devices, such as a mobilephone, a camera, a tablet personal computer, a personal digitalassistant (PDA) a vehicle camera or a head-mounted device (VR, AR, MR)and for taking pictures or for recording videos.

2. Description of the Prior Art

In recent years, an optical imaging lens improves along with its widerand wider applications. The applications of an optical imaging lens arenot only limited to take images and videos, but may also be used inenvironmental monitoring, dash cam photography, virtual reality tracker(VR tracker), facial recognition . . . etc. In addition to beinglighter, thinner, shorter and smaller, a design with a smaller F-number(Fno) facilitates the increase of the luminous flux along with theincrease of the field of view.

Accordingly, it is always a target of the design in the art to come upwith a lighter, thinner, shorter and smaller optical imaging lens with asmaller F-number, with a larger field of view and with good imagingquality at the same time to solve the problems. So a lighter, thinner,shorter and smaller optical imaging lens with a smaller F-number, with alarger field of view and with good imaging quality is still needed inthe art.

SUMMARY OF THE INVENTION

Accordingly, to solve the above problems, various embodiments of thepresent invention propose a lighter, thinner, shorter and smalleroptical imaging lens of six lens elements with a smaller F-number, witha larger field of view and with good imaging quality. The opticalimaging lens of six lens elements of the present invention from anobject side to an image side in order along an optical axis has a firstlens element, a second lens element, a third lens element, a fourth lenselement, a fifth lens element and a sixth lens element. Each first lenselement, second lens element, third lens element, fourth lens element,fifth lens element and sixth lens element has an object-side surfacewhich faces toward the object side and allows imaging rays to passthrough as well as an image-side surface which faces toward the imageside and allows the imaging rays to pass through.

In one embodiment, the first lens element has negative refracting power,the second lens element has negative refracting power and a peripheryregion of the object-side surface of the second lens element is convex,a periphery region of the image-side surface of the third lens elementis concave, and a periphery region of the object-side surface of thefifth lens element is concave and a periphery region of the image-sidesurface of the fifth lens element is concave. Lens elements included bythe optical imaging lens are only the six lens elements described aboveto satisfy the relationship: AAG/EFL≤2.700.

In another embodiment, an optical axis region of the object-side surfaceof the second lens element is convex, a periphery region of theobject-side surface of the third lens element is convex, an optical axisregion of the image-side surface of the third lens element is concave,and a periphery region of the object-side surface of the fifth lenselement is concave, an optical axis region of the image-side surface ofthe fifth lens element is concave and an optical axis region of theimage-side surface of the sixth lens element is convex. Lens elementsincluded by the optical imaging lens are only the six lens elementsdescribed above to satisfy the relationships: AAG/EFL≤2.700 andTTL/(EFL+BFL)≥1.800.

In another embodiment, the second lens element has negative refractingpower and a periphery region of the object-side surface of the secondlens element is convex, a periphery region of the image-side surface ofthe third lens element is concave, a periphery region of the object-sidesurface of the fifth lens element is concave and an optical axis regionof the image-side surface of the fifth lens element is concave. Lenselements included by the optical imaging lens are only the six lenselements described above to satisfy the relationships: AAG/EFL≤2.700 andTTL/(EFL+BFL)≥1.800.

In the optical imaging lens of the present invention, the embodimentsmay also selectively satisfy the following conditions:

TL/BFL≥1.800;  (1)

(AAG+BFL)/(T1+G12+T2)≤2.100;  (2)

|υ1−υ2|≤10.000;  (3)

(G45+T5+G56)/T6≤1.200;  (4)

ALT/AAG≥2.500;  (5)

Tmax/Gmax≥1.200;  (6)

TL/ALT≤1.700;  (7)

ALT/EFL≥3.300;  (8)

|υ4−υ6|≤6.500;  (9)

(T5+G56+T6)/(T3+T4)≤1.400;  (10)

(G12+G23)/T5≥3.000;  (11)

Gmax/Tmin≤2.400;  (12)

EFL/(G12+T2+G23)≤1.400;  (13)

AAG/(G23+T3)≤1.400;  (14)

υ3+υ4+υ5≤120.000;  (15)

(G12+G34+G45)/T2≤2.200;  (16)

(T3+G34)/(T1+T4)≤1.000.  (17)

In order to facilitate clearness of the parameters represented by thepresent invention and the drawings, it is defined in this specificationand the drawings: υ1 is an Abbe number of the first lens element, υ2 isan Abbe number of the second lens element, υ3 is an Abbe number of thethird lens element, υ4 is an Abbe number of the fourth lens element, υ5is an Abbe number of the fifth lens element and υ6 is an Abbe number ofthe sixth lens element. T1 is a thickness of the first lens elementalong the optical axis; T2 is a thickness of the second lens elementalong the optical axis; T3 is a thickness of the third lens elementalong the optical axis; T4 is a thickness of the fourth lens elementalong the optical axis; T5 is a thickness of the fifth lens elementalong the optical axis; and T6 is a thickness of the sixth lens elementalong the optical axis. Tmax is the largest thickness of a lens elementfrom the first lens element to the sixth lens element along the opticalaxis, that is, the largest thickness of T1, T2, T3, T4, T5 and T6. Tminis the smallest thickness of a lens element from the first lens elementto the sixth lens element along the optical axis, that is, the smallestthickness of T1, T2, T3, T4, T5 and T6.

G12 is an air gap between the first lens element and the second lenselement along the optical axis; G23 is an air gap between the secondlens element and the third lens element along the optical axis; G34 isan air gap between the third lens element and the fourth lens elementalong the optical axis; G45 is an air gap between the fourth lenselement and the fifth lens element along the optical axis; G56 is an airgap between the fifth lens element and the sixth lens element along theoptical axis. Gmax is the largest air gap from the first lens element tothe sixth lens element along the optical axis, that is, the largest airgap of G12, G23, G34, G45 and G56.

ALT is a sum of thicknesses of all the six lens elements along theoptical axis. TL is a distance from the object-side surface of the firstlens element to the image-side surface of the sixth lens element alongthe optical axis. TTL is a distance from the object-side surface of thefirst lens element to an image plane along the optical axis. BFL is adistance from the image-side surface of the sixth lens element to theimage plane along the optical axis. AAG is a sum of five air gaps fromthe first lens element to the sixth lens element along the optical axis.EFL is an effective focal length of the optical imaging lens.

These and other objectives of the present invention will no doubt becomeobvious to those of ordinary skill in the art after reading thefollowing detailed description of the preferred embodiment that isillustrated in the various figures and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1-5 illustrate the methods for determining the surface shapes andfor determining optical region or periphery region of one lens element.

FIG. 6 illustrates a first embodiment of the optical imaging lens of thepresent invention.

FIG. 7A illustrates the longitudinal spherical aberration on the imageplane of the first embodiment.

FIG. 7B illustrates the field curvature aberration on the sagittaldirection of the first embodiment.

FIG. 7C illustrates the field curvature aberration on the tangentialdirection of the first embodiment.

FIG. 7D illustrates the distortion of the first embodiment.

FIG. 8 illustrates a second embodiment of the optical imaging lens ofthe present invention.

FIG. 9A illustrates the longitudinal spherical aberration on the imageplane of the second embodiment.

FIG. 9B illustrates the field curvature aberration on the sagittaldirection of the second embodiment.

FIG. 9C illustrates the field curvature aberration on the tangentialdirection of the second embodiment.

FIG. 9D illustrates the distortion of the second embodiment.

FIG. 10 illustrates a third embodiment of the optical imaging lens ofthe present invention.

FIG. 11A illustrates the longitudinal spherical aberration on the imageplane of the third embodiment.

FIG. 11B illustrates the field curvature aberration on the sagittaldirection of the third embodiment.

FIG. 11C illustrates the field curvature aberration on the tangentialdirection of the third embodiment.

FIG. 11D illustrates the distortion of the third embodiment.

FIG. 12 illustrates a fourth embodiment of the optical imaging lens ofthe present invention.

FIG. 13A illustrates the longitudinal spherical aberration on the imageplane of the fourth embodiment.

FIG. 13B illustrates the field curvature aberration on the sagittaldirection of the fourth embodiment.

FIG. 13C illustrates the field curvature aberration on the tangentialdirection of the fourth embodiment.

FIG. 13D illustrates the distortion of the fourth embodiment.

FIG. 14 illustrates a fifth embodiment of the optical imaging lens ofthe present invention.

FIG. 15A illustrates the longitudinal spherical aberration on the imageplane of the fifth embodiment.

FIG. 15B illustrates the field curvature aberration on the sagittaldirection of the fifth embodiment.

FIG. 15C illustrates the field curvature aberration on the tangentialdirection of the fifth embodiment.

FIG. 15D illustrates the distortion of the fifth embodiment.

FIG. 16 illustrates a sixth embodiment of the optical imaging lens ofthe present invention.

FIG. 17A illustrates the longitudinal spherical aberration on the imageplane of the sixth embodiment.

FIG. 17B illustrates the field curvature aberration on the sagittaldirection of the sixth embodiment.

FIG. 17C illustrates the field curvature aberration on the tangentialdirection of the sixth embodiment.

FIG. 17D illustrates the distortion of the sixth embodiment.

FIG. 18 illustrates a seventh embodiment of the optical imaging lens ofthe present invention.

FIG. 19A illustrates the longitudinal spherical aberration on the imageplane of the seventh embodiment.

FIG. 19B illustrates the field curvature aberration on the sagittaldirection of the seventh embodiment.

FIG. 19C illustrates the field curvature aberration on the tangentialdirection of the seventh embodiment.

FIG. 19D illustrates the distortion of the seventh embodiment.

FIG. 20 illustrates an eighth embodiment of the optical imaging lens ofthe present invention.

FIG. 21A illustrates the longitudinal spherical aberration on the imageplane of the eighth embodiment.

FIG. 21B illustrates the field curvature aberration on the sagittaldirection of the eighth embodiment.

FIG. 21C illustrates the field curvature aberration on the tangentialdirection of the eighth embodiment.

FIG. 21D illustrates the distortion of the eighth embodiment.

FIG. 22 illustrates a ninth embodiment of the optical imaging lens ofthe present invention.

FIG. 23A illustrates the longitudinal spherical aberration on the imageplane of the ninth embodiment.

FIG. 23B illustrates the field curvature aberration on the sagittaldirection of the ninth embodiment.

FIG. 23C illustrates the field curvature aberration on the tangentialdirection of the ninth embodiment.

FIG. 23D illustrates the distortion of the ninth embodiment.

FIG. 24 shows the optical data of the first embodiment of the opticalimaging lens.

FIG. 25 shows the aspheric surface data of the first embodiment.

FIG. 26 shows the optical data of the second embodiment of the opticalimaging lens.

FIG. 27 shows the aspheric surface data of the second embodiment.

FIG. 28 shows the optical data of the third embodiment of the opticalimaging lens.

FIG. 29 shows the aspheric surface data of the third embodiment.

FIG. 30 shows the optical data of the fourth embodiment of the opticalimaging lens.

FIG. 31 shows the aspheric surface data of the fourth embodiment.

FIG. 32 shows the optical data of the fifth embodiment of the opticalimaging lens.

FIG. 33 shows the aspheric surface data of the fifth embodiment.

FIG. 34 shows the optical data of the sixth embodiment of the opticalimaging lens.

FIG. 35 shows the aspheric surface data of the sixth embodiment.

FIG. 36 shows the optical data of the seventh embodiment of the opticalimaging lens.

FIG. 37 shows the aspheric surface data of the seventh embodiment.

FIG. 38 shows the optical data of the eighth embodiment of the opticalimaging lens.

FIG. 39 shows the aspheric surface data of the eighth embodiment.

FIG. 40 shows the optical data of the ninth embodiment of the opticalimaging lens.

FIG. 41 shows the aspheric surface data of the ninth embodiment.

FIG. 42 shows some important ratios in the embodiments.

DETAILED DESCRIPTION

The terms “optical axis region”, “periphery region”, “concave”, and“convex” used in this specification and claims should be interpretedbased on the definition listed in the specification by the principle oflexicographer.

In the present disclosure, the optical system may comprise at least onelens element to receive imaging rays that are incident on the opticalsystem over a set of angles ranging from parallel to an optical axis toa half field of view (HFOV) angle with respect to the optical axis. Theimaging rays pass through the optical system to produce an image on animage plane. The term “a lens element having positive refracting power(or negative refracting power)” means that the paraxial refracting powerof the lens element in Gaussian optics is positive (or negative). Theterm “an object-side (or image-side) surface of a lens element” refersto a specific region of that surface of the lens element at whichimaging rays can pass through that specific region. Imaging rays includeat least two types of rays: a chief ray Lc and a marginal ray Lm (asshown in FIG. 1). An object-side (or image-side) surface of a lenselement can be characterized as having several regions, including anoptical axis region, a periphery region, and, in some cases, one or moreintermediate regions, as discussed more fully below.

FIG. 1 is a radial cross-sectional view of a lens element 100. Tworeferential points for the surfaces of the lens element 100 can bedefined: a central point, and a transition point. The central point of asurface of a lens element is a point of intersection of that surface andthe optical axis I. As illustrated in FIG. 1, a first central point CP1may be present on the object-side surface 110 of lens element 100 and asecond central point CP2 may be present on the image-side surface 120 ofthe lens element 100. The transition point is a point on a surface of alens element, at which the line tangent to that point is perpendicularto the optical axis I. The optical boundary OB of a surface of the lenselement is defined as a point at which the radially outermost marginalray Lm passing through the surface of the lens element intersects thesurface of the lens element. All transition points lie between theoptical axis I and the optical boundary OB of the surface of the lenselement. A surface of the lens element 100 may have no transition pointor have at least one transition point. If multiple transition points arepresent on a single surface, then these transition points aresequentially named along the radial direction of the surface withreference numerals starting from the first transition point. Forexample, the first transition point, e.g., TP1, (closest to the opticalaxis I), the second transition point, e.g., TP2, (as shown in FIG. 4),and the Nth transition point (farthest from the optical axis I).

When a surface of the lens element has at least one transition point,the region of the surface of the lens element from the central point tothe first transition point TP1 is defined as the optical axis region,which includes the central point. The region located radially outside ofthe farthest transition point (the Nth transition point) from theoptical axis I to the optical boundary OB of the surface of the lenselement is defined as the periphery region. In some embodiments, theremay be intermediate regions present between the optical axis region andthe periphery region, with the number of intermediate regions dependingon the number of the transition points. When a surface of the lenselement has no transition point, the optical axis region is defined as aregion of 0%-50% of the distance between the optical axis I and theoptical boundary OB of the surface of the lens element, and theperiphery region is defined as a region of 50%-100% of the distancebetween the optical axis I and the optical boundary OB of the surface ofthe lens element.

The shape of a region is convex if a collimated ray being parallel tothe optical axis I and passing through the region is bent toward theoptical axis I such that the ray intersects the optical axis I on theimage side A2 of the lens element. The shape of a region is concave ifthe extension line of a collimated ray being parallel to the opticalaxis I and passing through the region intersects the optical axis I onthe object side A1 of the lens element.

Additionally, referring to FIG. 1, the lens element 100 may also have amounting portion 130 extending radially outward from the opticalboundary OB. The mounting portion 130 is typically used to physicallysecure the lens element to a corresponding element of the optical system(not shown). Imaging rays do not reach the mounting portion 130. Thestructure and shape of the mounting portion 130 are only examples toexplain the technologies, and should not be taken as limiting the scopeof the present disclosure. The mounting portion 130 of the lens elementsdiscussed below may be partially or completely omitted in the followingdrawings.

Referring to FIG. 2, optical axis region Z1 is defined between centralpoint CP and first transition point TP1. Periphery region Z2 is definedbetween TP1 and the optical boundary OB of the surface of the lenselement. Collimated ray 211 intersects the optical axis I on the imageside A2 of lens element 200 after passing through optical axis regionZ1, i.e., the focal point of collimated ray 211 after passing throughoptical axis region Z1 is on the image side A2 of the lens element 200at point R in FIG. 2. Accordingly, since the ray itself intersects theoptical axis I on the image side A2 of the lens element 200, opticalaxis region Z1 is convex. On the contrary, collimated ray 212 divergesafter passing through periphery region Z2. The extension line EL ofcollimated ray 212 after passing through periphery region Z2 intersectsthe optical axis I on the object side A1 of lens element 200, i.e., thefocal point of collimated ray 212 after passing through periphery regionZ2 is on the object side A1 at point M in FIG. 2. Accordingly, since theextension line EL of the ray intersects the optical axis I on the objectside A1 of the lens element 200, periphery region Z2 is concave. In thelens element 200 illustrated in FIG. 2, the first transition point TP1is the border of the optical axis region and the periphery region, i.e.,TP1 is the point at which the shape changes from convex to concave.

Alternatively, there is another way for a person having ordinary skillin the art to determine whether an optical axis region is convex orconcave by referring to the sign of “Radius of curvature” (the “R”value), which is the paraxial radius of shape of a lens surface in theoptical axis region. The R value is commonly used in conventionaloptical design software such as Zemax and CodeV. The R value usuallyappears in the lens data sheet in the software. For an object-sidesurface, a positive R value defines that the optical axis region of theobject-side surface is convex, and a negative R value defines that theoptical axis region of the object-side surface is concave. Conversely,for an image-side surface, a positive R value defines that the opticalaxis region of the image-side surface is concave, and a negative R valuedefines that the optical axis region of the image-side surface isconvex. The result found by using this method should be consistent withthe method utilizing intersection of the optical axis by rays/extensionlines mentioned above, which determines surface shape by referring towhether the focal point of a collimated ray being parallel to theoptical axis I is on the object-side or the image-side of a lenselement. As used herein, the terms “a shape of a region is convex(concave),” “a region is convex (concave),” and “a convex- (concave-)region,” can be used alternatively.

FIG. 3, FIG. 4 and FIG. 5 illustrate examples of determining the shapeof lens element regions and the boundaries of regions under variouscircumstances, including the optical axis region, the periphery region,and intermediate regions as set forth in the present specification.

FIG. 3 is a radial cross-sectional view of a lens element 300. Asillustrated in FIG. 3, only one transition point TP1 appears within theoptical boundary OB of the image-side surface 320 of the lens element300. Optical axis region Z1 and periphery region Z2 of the image-sidesurface 320 of lens element 300 are illustrated. The R value of theimage-side surface 320 is positive (i.e., R>0). Accordingly, the opticalaxis region Z1 is concave.

In general, the shape of each region demarcated by the transition pointwill have an opposite shape to the shape of the adjacent region(s).Accordingly, the transition point will define a transition in shape,changing from concave to convex at the transition point or changing fromconvex to concave. In FIG. 3, since the shape of the optical axis regionZ1 is concave, the shape of the periphery region Z2 will be convex asthe shape changes at the transition point TP1.

FIG. 4 is a radial cross-sectional view of a lens element 400. Referringto FIG. 4, a first transition point TP1 and a second transition pointTP2 are present on the object-side surface 410 of lens element 400. Theoptical axis region Z1 of the object-side surface 410 is defined betweenthe optical axis I and the first transition point TP1. The R value ofthe object-side surface 410 is positive (i.e., R>0). Accordingly, theoptical axis region Z1 is convex.

The periphery region Z2 of the object-side surface 410, which is alsoconvex, is defined between the second transition point TP2 and theoptical boundary OB of the object-side surface 410 of the lens element400. Further, intermediate region Z3 of the object-side surface 410,which is concave, is defined between the first transition point TP1 andthe second transition point TP2. Referring once again to FIG. 4, theobject-side surface 410 includes an optical axis region Z1 locatedbetween the optical axis I and the first transition point TP1, anintermediate region Z3 located between the first transition point TP1and the second transition point TP2, and a periphery region Z2 locatedbetween the second transition point TP2 and the optical boundary OB ofthe object-side surface 410. Since the shape of the optical axis regionZ1 is designed to be convex, the shape of the intermediate region Z3 isconcave as the shape of the intermediate region Z3 changes at the firsttransition point TP1, and the shape of the periphery region Z2 is convexas the shape of the periphery region Z2 changes at the second transitionpoint TP2.

FIG. 5 is a radial cross-sectional view of a lens element 500. Lenselement 500 has no transition point on the object-side surface 510 ofthe lens element 500. For a surface of a lens element with no transitionpoint, for example, the object-side surface 510 the lens element 500,the optical axis region Z1 is defined as the region of 0%-50% of thedistance between the optical axis I and the optical boundary OB of thesurface of the lens element and the periphery region is defined as theregion of 50%-100% of the distance between the optical axis I and theoptical boundary OB of the surface of the lens element. Referring tolens element 500 illustrated in FIG. 5, the optical axis region Z1 ofthe object-side surface 510 is defined between the optical axis I and50% of the distance between the optical axis I and the optical boundaryOB. The R value of the object-side surface 510 is positive (i.e., R>0).Accordingly, the optical axis region Z1 is convex. For the object-sidesurface 510 of the lens element 500, because there is no transitionpoint, the periphery region Z2 of the object-side surface 510 is alsoconvex. It should be noted that lens element 500 may have a mountingportion (not shown) extending radially outward from the periphery regionZ2.

As shown in FIG. 6, the optical imaging lens 1 of six lens elements ofthe present invention, located from an object side A1 (where an objectis located) to an image side A2 along an optical axis I, is mainlycomposed of six lens elements, sequentially has a first lens element 10,a second lens element 20, a third lens element 30, an aperture stop 80,a fourth lens element 40, a fifth lens element 50, a sixth lens element60 and an image plane 91. The first lens element 10 may be made of aglass material to increase the ability against different environments,such as the thermal stability, abrasion-resistant, or anti-corrosion. Inaddition, when glass is selected for use in the third lens element 30,it may effectively increase the thermal stability and increase the yieldof the lens assembly. When the third lens element 30 is plastic, it mayeffectively increase the yield of the lens fabrication and reduce theweight of the optical imaging lens and reduce the production cost, butthe present invention is not limited thereto. Generally speaking, thesecond lens element 20, the fourth lens element 40, the fifth lenselement 50 and the sixth lens element 60 may be made of a transparentplastic material but the present invention is not limited to this, andeach lens element has an appropriate refracting power. In the opticalimaging lens 1 of the present invention, lens elements having refractingpower included by the optical imaging lens 1 are only the six lenselements (the first lens element 10, the second lens element 20, thethird lens element 30, the fourth lens element 40, the fifth lenselement 50 and the sixth lens element 60) described above. The opticalaxis I is the optical axis of the entire optical imaging lens 1, and theoptical axis of each of the lens elements coincides with the opticalaxis of the optical imaging lens 1.

Furthermore, the optical imaging lens 1 further includes an aperturestop (ape. stop) 80 disposed in an appropriate position. In FIG. 6, theaperture stop 80 is disposed between the third lens element 30 and thefourth lens element 40. When imaging rays emitted or reflected by anobject (not shown) which is located at the object side A1 enters theoptical imaging lens 1 of the present invention, the imaging rays form aclear and sharp image on the image plane 91 at the image side A2 afterpassing through the first lens element 10, the second lens element 20,the third lens element 30, the aperture stop 80, the fourth lens element40, the fifth lens element 50, the sixth lens element 60, and a filter90. In the embodiments of the present invention, the filter 90 may be afilter of various suitable functions, placed between the sixth lenselement 60 and the image plane 91 to filter out light of a specificwavelength, for some embodiments, the filter 90 may be an infrared cutfilter (infrared cut-off filter), to keep the infrared light in theimaging rays from reaching the image plane 91 to jeopardize the imagingquality.

Each lens element of the optical imaging lens 1 has an object-sidesurface facing toward the object side A1 and allowing imaging rays topass through as well as an image-side surface facing toward the imageside A2 and allowing the imaging rays to pass through. In addition, eachlens element of the optical imaging lens 1 has an optical axis regionand a periphery region. For example, the first lens element 10 has anobject-side surface 11 and an image-side surface 12; the second lenselement 20 has an object-side surface 21 and an image-side surface 22;the third lens element 30 has an object-side surface 31 and animage-side surface 32; the fourth lens element 40 has an object-sidesurface 41 and an image-side surface 42; the fifth lens element 50 hasan object-side surface 51 and an image-side surface 52; the sixth lenselement 60 has an object-side surface 61 and an image-side surface 62.Furthermore, each object-side surface and image-side surface of lenselements in the optical imaging lens of present invention has an opticalaxis region and a periphery region.

Each lens element in the optical imaging lens 1 of the present inventionfurther has a thickness T along the optical axis I. For embodiment, thefirst lens element 10 has a first lens element thickness T1, the secondlens element 20 has a second lens element thickness T2, the third lenselement 30 has a third lens element thickness T3, the fourth lenselement 40 has a fourth lens element thickness T4, the fifth lenselement 50 has a fifth lens element thickness T5, and the sixth lenselement 60 has a sixth lens element thickness T6. Therefore, a sum ofthicknesses of all the six lens elements from the first lens element 10to the sixth lens element 60 in the optical imaging lens 1 along theoptical axis I is ALT. In other words, ALT=T1+T2+T3+T4+T5+T6. Tmax isthe largest thickness of a lens element from the first lens element 10to the sixth lens element 60 along the optical axis I, that is, thelargest thickness of T1, T2, T3, T4, T5 and T6. Tmin is the smallestthickness of a lens element from the first lens element 10 to the sixthlens element 60 along the optical axis I, that is, the smallestthickness of T1, T2, T3, T4, T5 and T6.

In addition, between two adjacent lens elements in the optical imaginglens 1 of the present invention there may be an air gap along theoptical axis I. For example, there is an air gap G12 between the firstlens element 10 and the second lens element 20, an air gap G23 betweenthe second lens element 20 and the third lens element 30, an air gap G34between the third lens element 30 and the fourth lens element 40, an airgap G45 between the fourth lens element 40 and the fifth lens element 50as well as an air gap G56 between the fifth lens element 50 and thesixth lens element 60. Therefore, a sum of five air gaps from the firstlens element 10 to the sixth lens element 60 along the optical axis I isAAG. In other words, AAG=G12+G23+G34+G45+G56. Gmax is the largest airgap from the first lens element 10 to the sixth lens element 60 alongthe optical axis I, that is, the largest air gap of G12, G23, G34, G45and G56.

In addition, a distance from the object-side surface 11 of the firstlens element 10 to the image plane 91, namely a system length of theoptical imaging lens 1 along the optical axis I is TTL. An effectivefocal length of the optical imaging lens is EFL. A distance from theobject-side surface 11 of the first lens element 10 to the image-sidesurface 62 of the sixth lens element 60 along the optical axis I is TL.HFOV stands for the half field of view of the optical imaging lens 1,which is a half of the field of view. ImgH is an image height of theoptical imaging lens 1. Fno is the f-number of the optical imaging lens1.

When the filter 90 is placed between the sixth lens element 60 and theimage plane 91, an air gap between the sixth lens element 60 and thefilter 90 along the optical axis I is G6F; a thickness of the filter 90along the optical axis I is TF; an air gap between the filter 90 and theimage plane 91 along the optical axis I is GFP. BFL is the back focallength of the optical imaging lens 1, namely a distance from theimage-side surface 62 of the sixth lens element 60 to the image plane 91along the optical axis I. Therefore, BFL=G6F+TF+GFP.

Furthermore, a focal length of the first lens element 10 is f1; a focallength of the second lens element 20 is f2; a focal length of the thirdlens element 30 is f3; a focal length of the fourth lens element 40 isf4; a focal length of the fifth lens element 50 is f5; a focal length ofthe sixth lens element 60 is f6; a refractive index of the first lenselement 10 is n1; a refractive index of the second lens element 20 isn2; a refractive index of the third lens element 30 is n3; a refractiveindex of the fourth lens element 40 is n4; a refractive index of thefifth lens element 50 is n5; a refractive index of the sixth lenselement 60 is n6; an Abbe number of the first lens element 10 is υ1; anAbbe number of the second lens element 20 is υ2; an Abbe number of thethird lens element 30 is υ3; and an Abbe number of the fourth lenselement 40 is υ4; an Abbe number of the fifth lens element 50 is υ5; andan Abbe number of the sixth lens element 60 is υ6.

First Embodiment

Please refer to FIG. 6 which illustrates the first embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG. 7Afor the longitudinal spherical aberration on the image plane 91 of thefirst embodiment; please refer to FIG. 7B for the field curvatureaberration on the sagittal direction; please refer to FIG. 7C for thefield curvature aberration on the tangential direction; and please referto FIG. 7D for the distortion aberration. The Y axis of the sphericalaberration in each embodiment is “field of view” for 1.0. The Y axis ofthe field curvature aberration and the distortion aberration in eachembodiment stands for the “image height” (ImgH), which is 1.026 mm.

Lens elements included by the optical imaging lens 1 in the firstembodiment are only the six lens elements described, an aperture stop 80and an image plane 91. The aperture stop 80 in the first embodiment isprovided between the third lens element 30 and the fourth lens element40.

The first lens element 10 has negative refracting power. An optical axisregion 13 and a periphery region 14 of the object-side surface 11 of thefirst lens element 10 are concave. An optical axis region 16 and aperiphery region 17 of the image-side surface 12 of the first lenselement 10 are concave. Besides, both the object-side surface 11 and theimage-side surface 12 of the first lens element 10 are sphericalsurfaces, but it is not limited thereto. The material of the first lenselement 10 is glass, but it is not limited thereto.

The second lens element 20 has negative refracting power. An opticalaxis region 23 and a periphery region 24 of the object-side surface 21of the second lens element 20 are convex. An optical axis region 26 anda periphery region 27 of the image-side surface 22 of the second lenselement 20 are concave. Besides, both the object-side surface 21 and theimage-side surface 22 of the second lens element 20 are asphericalsurfaces, but it is not limited thereto. The material of the second lenselement 20 is plastic, but it is not limited thereto.

The third lens element 30 has positive refracting power. An optical axisregion 33 and a periphery region 34 of the object-side surface 31 of thethird lens element 30 are convex. An optical axis region 36 and aperiphery region 37 of the image-side surface 32 of the third lenselement 30 are concave. Besides, both the object-side surface 31 and theimage-side surface 32 of the third lens element 30 are asphericalsurfaces, but it is not limited thereto. The material of the third lenselement 30 is plastic, but it is not limited thereto.

The fourth lens element 40 has positive refracting power. An opticalaxis region 43 and a periphery region 44 of the object-side surface 41of the fourth lens element 40 are convex. An optical axis region 46 anda periphery region 47 of the image-side surface 42 of the fourth lenselement 40 are convex. Besides, both the object-side surface 41 and theimage-side surface 42 of the fourth lens element 40 are asphericalsurfaces, but it is not limited thereto. The material of the fourth lenselement 40 is plastic, but it is not limited thereto.

The fifth lens element 50 has negative refracting power. An optical axisregion 53 and a periphery region 54 of the object-side surface 51 of thefifth lens element 50 are concave. An optical axis region 56 and aperiphery region 57 of the image-side surface 52 of the fifth lenselement 50 are concave. Besides, both the object-side surface 51 and theimage-side surface 52 of the fifth lens element 50 are asphericalsurfaces, but it is not limited thereto. The material of the fifth lenselement 50 is plastic, but it is not limited thereto.

The sixth lens element 60 has positive refracting power. An optical axisregion 63 and a periphery region 64 of the object-side surface 61 of thesixth lens element 60 are convex. An optical axis region 66 and aperiphery region 67 of the image-side surface 62 of the sixth lenselement 60 are convex. Besides, both the object-side surface 61 and theimage-side surface 62 of the sixth lens element 60 are asphericalsurfaces, but it is not limited thereto. The material of the sixth lenselement 60 is plastic, but it is not limited thereto.

In the optical imaging lens element 1 of the present invention, from thesecond lens element 20 to the sixth lens element 60, all the 10surfaces, such as the object-side surfaces 21/31/41/51/61 and theimage-side surfaces 22/32/42/52/62 are aspherical surfaces, but they arenot limited thereto. If a surface is aspherical, these asphericcoefficients are defined according to the following formula:

${Z(Y)} = {{\frac{Y^{2}}{R}/\left( {1 + \sqrt{1 - {\left( {1 + K} \right)\frac{Y^{2}}{R^{2}}}}} \right)} + {\sum\limits_{j = 1}^{n}{a_{i} \times Y^{i}}}}$

In which:

Y represents a vertical distance from a point on the aspherical surfaceto the optical axis I;Z represents the depth of an aspherical surface (the perpendiculardistance between the point of the aspherical surface at a distance Yfrom the optical axis I and the tangent plane of the vertex on theoptical axis I of the aspherical surface);R represents the radius of curvature of the lens element surface closeto the optical axis I;K is a conic constant; anda_(i) is the aspheric coefficient of the i^(th) order.

The optical data of the first embodiment of the optical imaging lens 1are shown in FIG. 24 while the aspheric surface data are shown in FIG.25. All of the a₂ of the aspheric coefficient of the second order are 0in the present embodiment and in the following embodiments. In thepresent embodiments of the optical imaging lens, the f-number of theentire optical imaging lens is Fno, EFL is the effective focal length,HFOV stands for the half field of view of the entire optical imaginglens, and the unit for the radius of curvature, the thickness and thefocal length is in millimeters (mm). In this embodiment, EFL=0.850 mm;HFOV=77.751 degrees; TTL=5.467 mm; Fno=2.200; ImgH=1.026 mm.

Second Embodiment

Please refer to FIG. 8 which illustrates the second embodiment of theoptical imaging lens 1 of the present invention. It is noted that fromthe second embodiment to the following embodiments, in order to simplifythe figures, only the components different from what the firstembodiment has, and the basic lens elements will be labeled in figures.Other components that are the same as what the first embodiment has,such as a convex surface or a concave surface, are omitted in thefollowing embodiments. Please refer to FIG. 9A for the longitudinalspherical aberration on the image plane 91 of the second embodiment,please refer to FIG. 9B for the field curvature aberration on thesagittal direction, please refer to FIG. 9C for the field curvatureaberration on the tangential direction, and please refer to FIG. 9D forthe distortion aberration. The components in this embodiment are similarto those in the first embodiment, but the optical data such as therefracting power, the radius of curvature, the lens thickness, theaspheric surface or the back focal length in this embodiment aredifferent from the optical data in the first embodiment. Besides, inthis embodiment, the optical axis region 13 of the object-side surface11 of the first lens element 10 is convex, the periphery region 14 ofthe object-side surface 11 of the first lens element 10 is convex andthe periphery region 67 of the image-side surface 62 of the sixth lenselement 60 is concave.

The optical data of the second embodiment of the optical imaging lensare shown in FIG. 26 while the aspheric surface data are shown in FIG.27. In this embodiment, EFL=0.502 mm; HFOV=76.779 degrees; TTL=5.503 mm;Fno=2.200; ImgH=0.883 mm. In particular, 1) the longitudinal sphericalaberration of the optical imaging lens in this embodiment is better thanthat of the optical imaging lens in the first embodiment, 2) the fieldcurvature aberration on the sagittal direction of the optical imaginglens in this embodiment is better than that of the optical imaging lensin the first embodiment, 3) the field curvature aberration on thetangential direction of the optical imaging lens in this embodiment isbetter than that of the optical imaging lens in the first embodiment,and 4) the distortion aberration of the optical imaging lens in thisembodiment is better than that of the optical imaging lens in the firstembodiment.

Third Embodiment

Please refer to FIG. 10 which illustrates the third embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.11A for the longitudinal spherical aberration on the image plane 91 ofthe third embodiment; please refer to FIG. 11B for the field curvatureaberration on the sagittal direction; please refer to FIG. 11C for thefield curvature aberration on the tangential direction; and please referto FIG. 11D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the optical axis region 13 of theobject-side surface 11 of the first lens element 10 is convex, theperiphery region 14 of the object-side surface 11 of the first lenselement 10 is convex, the third lens element 30 has negative refractingpower and the periphery region 67 of the image-side surface 62 of thesixth lens element 60 is concave.

The optical data of the third embodiment of the optical imaging lens areshown in FIG. 28 while the aspheric surface data are shown in FIG. 29.In this embodiment, EFL=0.881 mm; HFOV=51.022 degrees; TTL=5.066 mm;Fno=2.200; ImgH=0.972 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, 2) the longitudinal spherical aberration of theoptical imaging lens in this embodiment is better than that of theoptical imaging lens in the first embodiment, and 3) the distortionaberration of the optical imaging lens in this embodiment is better thanthat of the optical imaging lens in the first embodiment.

Fourth Embodiment

Please refer to FIG. 12 which illustrates the fourth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.13A for the longitudinal spherical aberration on the image plane 91 ofthe fourth embodiment; please refer to FIG. 13B for the field curvatureaberration on the sagittal direction; please refer to FIG. 13C for thefield curvature aberration on the tangential direction; and please referto FIG. 13D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the optical axis region 16 of theimage-side surface 12 of the first lens element 10 is convex, theperiphery region 17 of the image-side surface 12 of the first lenselement 10 is convex and the periphery region 67 of the image-sidesurface 62 of the sixth lens element 60 is concave.

The optical data of the fourth embodiment of the optical imaging lensare shown in FIG. 30 while the aspheric surface data are shown in FIG.31. In this embodiment, EFL=0.724 mm; HFOV=76.779 degrees; TTL=5.311 mm;Fno=2.200; ImgH=1.049 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, 2) the longitudinal spherical aberration of theoptical imaging lens in this embodiment is better than that of theoptical imaging lens in the first embodiment, 3) the field curvatureaberration on the sagittal direction of the optical imaging lens in thisembodiment is better than that of the optical imaging lens in the firstembodiment, 4) the field curvature aberration on the tangentialdirection of the optical imaging lens in this embodiment is better thanthat of the optical imaging lens in the first embodiment, and 5) thedistortion aberration of the optical imaging lens in this embodiment isbetter than that of the optical imaging lens in the first embodiment.

Fifth Embodiment

Please refer to FIG. 14 which illustrates the fifth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.15A for the longitudinal spherical aberration on the image plane 91 ofthe fifth embodiment; please refer to FIG. 15B for the field curvatureaberration on the sagittal direction; please refer to FIG. 15C for thefield curvature aberration on the tangential direction, and please referto FIG. 15D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the optical axis region 13 of theobject-side surface 11 of the first lens element 10 is convex, theperiphery region 14 of the object-side surface 11 of the first lenselement 10 is convex, the periphery region 37 of the image-side surface32 of the third lens element 30 is convex, and the periphery region 67of the image-side surface 62 of the sixth lens element 60 is concave.

The optical data of the fifth embodiment of the optical imaging lens areshown in FIG. 32 while the aspheric surface data are shown in FIG. 33.In this embodiment, EFL=0.622 mm; HFOV=76.779 degrees; TTL=4.627 mm;Fno=2.200; ImgH=1.049 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, 2) the longitudinal spherical aberration of theoptical imaging lens in this embodiment is better than that of theoptical imaging lens in the first embodiment, 3) the field curvatureaberration on the sagittal direction of the optical imaging lens in thisembodiment is better than that of the optical imaging lens in the firstembodiment, 4) the field curvature aberration on the tangentialdirection of the optical imaging lens in this embodiment is better thanthat of the optical imaging lens in the first embodiment, and 5) thedistortion aberration of the optical imaging lens in this embodiment isbetter than that of the optical imaging lens in the first embodiment.

Sixth Embodiment

Please refer to FIG. 16 which illustrates the sixth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.17A for the longitudinal spherical aberration on the image plane 91 ofthe sixth embodiment; please refer to FIG. 17B for the field curvatureaberration on the sagittal direction; please refer to FIG. 17C for thefield curvature aberration on the tangential direction, and please referto FIG. 17D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the optical axis region 13 of theobject-side surface 11 of the first lens element 10 is convex, theperiphery region 14 of the object-side surface 11 of the first lenselement 10 is convex, and the material of the third lens element 30 isglass.

The optical data of the sixth embodiment of the optical imaging lens areshown in FIG. 34 while the aspheric surface data are shown in FIG. 35.In this embodiment, EFL=0.766 mm; HFOV=76.779 degrees; TTL=5.035 mm;Fno=2.200; ImgH=0.974 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, 2) the field curvature aberration on thetangential direction of the optical imaging lens in this embodiment isbetter than that of the optical imaging lens in the first embodiment,and 3) the distortion aberration of the optical imaging lens in thisembodiment is better than that of the optical imaging lens in the firstembodiment.

Seventh Embodiment

Please refer to FIG. 18 which illustrates the seventh embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.19A for the longitudinal spherical aberration on the image plane 91 ofthe seventh embodiment; please refer to FIG. 19B for the field curvatureaberration on the sagittal direction; please refer to FIG. 19C for thefield curvature aberration on the tangential direction, and please referto FIG. 19D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the periphery region 67 of the image-sidesurface 62 of the sixth lens element 60 is concave.

The optical data of the seventh embodiment of the optical imaging lensare shown in FIG. 36 while the aspheric surface data are shown in FIG.37. In this embodiment, EFL=0.741 mm; HFOV=76.779 degrees; TTL=4.548 mm;Fno=2.200; ImgH=0.972 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, 2) the longitudinal spherical aberration of theoptical imaging lens in this embodiment is better than that of theoptical imaging lens in the first embodiment, 3) the field curvatureaberration on the tangential direction of the optical imaging lens inthis embodiment is better than that of the optical imaging lens in thefirst embodiment, and 4) the distortion aberration of the opticalimaging lens in this embodiment is better than that of the opticalimaging lens in the first embodiment.

Eighth Embodiment

Please refer to FIG. 20 which illustrates the eighth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.21A for the longitudinal spherical aberration on the image plane 91 ofthe eighth embodiment; please refer to FIG. 21B for the field curvatureaberration on the sagittal direction; please refer to FIG. 21C for thefield curvature aberration on the tangential direction, and please referto FIG. 21D for the distortion aberration. The components in thisembodiment are similar to those in the first embodiment, but the opticaldata such as the refracting power, the radius of curvature, the lensthickness, the aspheric surface or the back focal length in thisembodiment are different from the optical data in the first embodiment.Besides, in this embodiment, the periphery region 67 of the image-sidesurface 62 of the sixth lens element 60 is concave.

The optical data of the eighth embodiment of the optical imaging lensare shown in FIG. 38 while the aspheric surface data are shown in FIG.39. In this embodiment, EFL=0.761 mm; HFOV=76.779 degrees; TTL=4.734 mm;Fno=2.200; ImgH=0.973 mm. In particular, 1) TTL of the optical imaginglens in this embodiment is shorter than that of the optical imaging lensin the first embodiment, and 2) the distortion aberration of the opticalimaging lens in this embodiment is better than that of the opticalimaging lens in the first embodiment.

Ninth Embodiment

Please refer to FIG. 22 which illustrates the ninth embodiment of theoptical imaging lens 1 of the present invention. Please refer to FIG.23A for the longitudinal spherical aberration on the image plane 91 ofthe ninth embodiment; please refer to FIG. 23B for the field curvatureaberration on the sagittal direction; please refer to FIG. 23C for thefield curvature aberration on the tangential direction, and please referto FIG. 23D for the distortion aberration. The components in thisexample are similar to those in the first embodiment, but the opticaldata such as the curvature radius of curvature, the lens thickness, theaspheric surface or the back focal length in this embodiment aredifferent from the optical data in the first embodiment. Besides, inthis embodiment, the fifth lens element 50 has positive refractingpower, the optical axis region 53 of the object-side surface 51 of thefifth lens element 50 is convex, the sixth lens element 60 has negativerefracting power, the optical axis region 63 of the object-side surface61 of the sixth lens element 60 is concave and the periphery region 64of the object-side surface 61 of the sixth lens element 60 is concave.

The optical data of the ninth embodiment of the optical imaging lens areshown in FIG. 40 while the aspheric surface data are shown in FIG. 41.In this embodiment, EFL=0.457 mm; HFOV=76.779 degrees; TTL=4.208 mm;Fno=2.200; ImgH=0.972 mm. In particular: the system length of theoptical imaging lens TTL in this embodiment is shorter than the systemlength of the optical imaging lens TTL in the first embodiment.

Some important ratios in each embodiment are shown in FIG. 42.

The embodiments of the present invention provide an optical imaging lenswith good imaging quality. Furthermore, the present invention has theadvantageous efficacy:

1. When the first lens element has negative refracting power, the secondlens element has negative refracting power, the periphery region of theobject-side surface of the second lens element is convex, the peripheryregion of the image-side surface of the third lens element is concave,and the periphery region of the object-side surface of the fifth lenselement is concave and the periphery region of the image-side surface ofthe fifth lens element is concave to satisfy AAG/EFL≤2.700, thecombination may facilitate to maintain good imaging quality whileeffectively increasing the HFOV of the entire optical imaging lens. Thepreferable range may be 0.750≤AAG/EFL≤2.700.2. When the periphery region of the object-side surface of the fifthlens element is concave, the optical axis region of the image-sidesurface of the fifth lens element is concave, AAG/EFL≤2.700 andTTL/(EFL+BFL)≥1.800, the combination may facilitate to maintain goodimaging quality while effectively increasing the HFOV and decreasing thesystem length TTL of the optical imaging lens. They may further go with:(a) the optical axis region of the object-side surface of the secondlens element is convex, the periphery region of the object-side surfaceof the third lens element is convex and the optical axis region of theimage-side surface of the third lens element is concave and the opticalaxis region of the image-side surface of the six lens element is convex,or(b) the second lens element has negative refracting power, the peripheryregion of the object-side surface of the second lens element is convex,and the periphery region of the image-side surface of the third lenselement is concave, either one of the above combinations may furtherimprove the aberration. The preferable range of AAG/EFL may be0.750≤AAG/EFL≤2.700; the preferable range of TTL/(EFL+BFL) may be1.800≤TTL/(EFL+BFL)≤4.700.3. Through the selection of materials of specific lens elements, it mayincrease the ability against different environments, such as the thermalstability, abrasion-resistant, or anti-corrosion when the first lenselement uses a glass material. In addition, it may effectively increasethe thermal stability and increase the yield of the lens assembly whenglass is selected for use in the third lens element. When the third lenselement uses a plastic material, it may effectively increase the yieldof the lens fabrication, reduce the weight of the optical imaging lensand reduce the production cost.4. Through the configuration of appropriate materials, it is beneficialto the transmission and deflection of imaging rays and to improve thechromatic aberration of the entire optical imaging lens when thefollowing limitations are met.(1) |υ1−υ2|≤10.000, the preferable range is 5.700≤|υ1−υ2|≤10.000;(2) |υ4−υ6|≤6.500, the preferable range is 0.000≤|υ4−υ6|≤6.500;(3) υ3+υ4+υ5≤120.000, the preferable range is 85.000≤υ3+υ4+υ5≤120.0005. In order to reduce the system length of the optical imaging lensalong the optical axis I and to ensure the imaging quality, the air gapsbetween lens elements or the thickness of each lens element should beappropriately reduced and the assembly or the manufacturing difficultyshould be taken into consideration as well. If the following numericalconditions are satisfied, they may facilitate better arrangements of theembodiments of the present invention:(1) TL/BFL≥1.800, and the preferable range is 1.800≤TL/BFL≤6.800;(2) (AAG+BFL)/(T1+G12+T2)≤2.100, and the preferable range is1.000≤(AAG+BFL)/(T1+G12+T2)≤2.100;(3) (G45+T5+G56)/T6≤1.200, and the preferable range is0.250≤(G45+T5+G56)/T6≤1.200;(4) ALT/AAG≥2.500, and the preferable range is 2.500≤ALT/AAG≤5.000;(5) Tmax/Gmax≥1.200, and the preferable range is 1.200≤Tmax/Gmax≤3.000;(6) TL/ALT≤1.700, and the preferable range is 1.100≤TL/ALT≤1.700;(7) ALT/EFL≥3.300, and the preferable range is 3.300≤ALT/EFL≤7.400;(8) (T5+G56+T6)/(T3+T4)≤1.400, and the preferable range is0.350≤(T5+G56+T6)/(T3+T4)≤1.400;(9) (G12+G23)/T5≥3.000, and the preferable range is3.000≤(G12+G23)/T5≤4.600;(10) Gmax/Tmin≤2.400, and the preferable range is 1.600≤Gmax/Tmin≤2.400;(11) EFL/(G12+T2+G23)≤1.400, and the preferable range is0.300≤EFL/(G12+T2+G23)≤1.400;(12) AAG/(G23+T3)≤1.400, and the preferable range is0.550≤AAG/(G23+T3)≤1.400;(13) (G12+G34+G45)/T2≤2.200, and the preferable range is0.520≤(G12+G34+G45)/T2≤2.200;(14) (T3+G34)/(T1+T4)≤1.000, and the preferable range is0.250≤(T3+G34)/(T1+T4)≤1.000; and(15) TTL/AAG≥3.500, and the preferable range is 3.500≤TTL/AAG≤8.500.

Any arbitrary combination of the parameters of the embodiments can beselected additionally to increase the lens limitation so as tofacilitate the design of the same structure of the present invention.

In the light of the unpredictability of the optical imaging lens, theabove conditional formulas preferably suggest the above principles tohave a shorter system length of the optical imaging lens, an enlargedfield of view, better imaging quality or a better fabrication yield toovercome the drawbacks of prior art. Some of the lens elements in theembodiments of the present invention may be made of a plastic materialto reduce the weight of the optical imaging lens and to reduce theproduction cost.

The contents in the embodiments of the invention include but are notlimited to a focal length, a thickness of a lens element, an Abbenumber, or other optical parameters. For example, in the embodiments ofthe invention, an optical parameter A and an optical parameter B aredisclosed, wherein the ranges of the optical parameters, comparativerelation between the optical parameters, and the range of a conditionalexpression covered by a plurality of embodiments are specificallyexplained as follows:

(1) The ranges of the optical parameters are, for example, α₂≤A≤α₁ orβ₂≤B≤β₁, where α₁ is a maximum value of the optical parameter A amongthe plurality of embodiments, α₂ is a minimum value of the opticalparameter A among the plurality of embodiments, β₁ is a maximum value ofthe optical parameter B among the plurality of embodiments, and β₂ is aminimum value of the optical parameter B among the plurality ofembodiments.(2) The comparative relation between the optical parameters is that A isgreater than B or A is less than B, for example.(3) The range of a conditional expression covered by a plurality ofembodiments is in detail a combination relation or proportional relationobtained by a possible operation of a plurality of optical parameters ineach same embodiment. The relation is defined as E, and E is, forexample, A+B or A-B or A/B or A*B or (A*B)^(1/2), and E satisfies aconditional expression E≤γ₁ or E≤γ₂ or γ₂≤E≤γ₁, where each of γ₁ and γ₂is a value obtained by an operation of the optical parameter A and theoptical parameter B in a same embodiment, γ₁ is a maximum value amongthe plurality of the embodiments, and γ₂ is a minimum value among theplurality of the embodiments.

The ranges of the aforementioned optical parameters, the aforementionedcomparative relations between the optical parameters, and a maximumvalue, a minimum value, and the numerical range between the maximumvalue and the minimum value of the aforementioned conditionalexpressions are all implementable and all belong to the scope disclosedby the invention. The aforementioned description is for exemplaryexplanation, but the invention is not limited thereto.

The embodiments of the invention are all implementable. In addition, acombination of partial features in a same embodiment can be selected,and the combination of partial features can achieve the unexpectedresult of the invention with respect to the prior art. The combinationof partial features includes but is not limited to the surface shape ofa lens element, a refracting power, a conditional expression or thelike, or a combination thereof. The description of the embodiments isfor explaining the specific embodiments of the principles of theinvention, but the invention is not limited thereto. Specifically, theembodiments and the drawings are for exemplifying, but the invention isnot limited thereto.

Those skilled in the art will readily observe that numerousmodifications and alterations of the device and method may be made whileretaining the teachings of the invention. Accordingly, the abovedisclosure should be construed as limited only by the metes and boundsof the appended claims.

What is claimed is:
 1. An optical imaging lens, from an object side toan image side in order along an optical axis comprising: a first lenselement, a second lens element, a third lens element, a fourth lenselement, a fifth lens element, and a sixth lens element, the first lenselement to the sixth lens element each having an object-side surfacefacing toward the object side and allowing imaging rays to pass throughas well as an image-side surface facing toward the image side andallowing the imaging rays to pass through; the first lens element hasnegative refracting power; the second lens element has negativerefracting power and a periphery region of the object-side surface ofthe second lens element is convex; a periphery region of the image-sidesurface of the third lens element is concave; and a periphery region ofthe object-side surface of the fifth lens element is concave and aperiphery region of the image-side surface of the fifth lens element isconcave; wherein lens elements included by the optical imaging lens areonly the six lens elements described above, AAG is a sum of five airgaps from the first lens element to the sixth lens element along theoptical axis, and EFL is an effective focal length of the opticalimaging lens to satisfy the relationship: AAG/EFL≤2.700.
 2. The opticalimaging lens of claim 1, wherein TL is a distance from the object-sidesurface of the first lens element to the image-side surface of the sixthlens element along the optical axis and BFL is a distance from theimage-side surface of the sixth lens element to an image plane along theoptical axis, and the optical imaging lens satisfies the relationship:TL/BFL≥1.800.
 3. The optical imaging lens of claim 1, wherein T1 is athickness of the first lens element along the optical axis, T2 is athickness of the second lens element along the optical axis and G12 isan air gap between the first lens element and the second lens elementalong the optical axis and BFL is a distance from the image-side surfaceof the sixth lens element to an image plane along the optical axis, andthe optical imaging lens satisfies the relationship:(AAG+BFL)/(T1+G12+T2)≤2.100.
 4. The optical imaging lens of claim 1,wherein υ1 is an Abbe number of the first lens element and υ2 is an Abbenumber of the second lens element, and the optical imaging lenssatisfies the relationship: |υ1−υ2|≤10.000.
 5. The optical imaging lensof claim 1, wherein T5 is a thickness of the fifth lens element alongthe optical axis, T6 is a thickness of the sixth lens element along theoptical axis, G45 is an air gap between the fourth lens element and thefifth lens element along the optical axis and G56 is an air gap betweenthe fifth lens element and the sixth lens element along the opticalaxis, and the optical imaging lens satisfies the relationship:(G45+T5+G56)/T6≤1.200.
 6. The optical imaging lens of claim 1, whereinALT is a sum of thicknesses of all the six lens elements along theoptical axis, and the optical imaging lens satisfies the relationship:ALT/AAG≥2.500.
 7. The optical imaging lens of claim 1, wherein Tmax isthe largest thickness of a lens element from the first lens element tothe sixth lens element along the optical axis and Gmax is the largestair gap from the first lens element to the sixth lens element along theoptical axis, and the optical imaging lens satisfies the relationship:Tmax/Gmax≥1.200.
 8. An optical imaging lens, from an object side to animage side in order along an optical axis comprising: a first lenselement, a second lens element, a third lens element, a fourth lenselement, a fifth lens element, and a sixth lens element, the first lenselement to the sixth lens element each having an object-side surfacefacing toward the object side and allowing imaging rays to pass throughas well as an image-side surface facing toward the image side andallowing the imaging rays to pass through; the second lens element hasnegative refracting power and a periphery region of the object-sidesurface of the second lens element is convex; a periphery region of theimage-side surface of the third lens element is concave; and a peripheryregion of the object-side surface of the fifth lens element is concaveand an optical axis region of the image-side surface of the fifth lenselement is concave; wherein lens elements included by the opticalimaging lens are only the six lens elements described above, AAG is asum of five air gaps from the first lens element to the sixth lenselement along the optical axis, EFL is an effective focal length of theoptical imaging lens, TTL is a distance from the object-side surface ofthe first lens element to an image plane along the optical axis, and BFLis a distance from the image-side surface of the sixth lens element tothe image plane along the optical axis to satisfy the relationships:AAG/EFL≤2.700 and TTL/(EFL+BFL)≥1.800.
 9. The optical imaging lens ofclaim 8, wherein TL is a distance from the object-side surface of thefirst lens element to the image-side surface of the sixth lens elementalong the optical axis and ALT is a sum of thicknesses of all the sixlens elements along the optical axis, and the optical imaging lenssatisfies the relationship: TL/ALT≤1.700.
 10. The optical imaging lensof claim 8, wherein ALT is a sum of thicknesses of all the six lenselements along the optical axis, and the optical imaging lens satisfiesthe relationship: ALT/EFL≥3.300.
 11. The optical imaging lens of claim8, wherein υ4 is an Abbe number of the fourth lens element and υ6 is anAbbe number of the sixth lens element, and the optical imaging lenssatisfies the relationship: |υ4−υ6|≤6.500.
 12. The optical imaging lensof claim 8, wherein T3 is a thickness of the third lens element alongthe optical axis, T4 is a thickness of the fourth lens element along theoptical axis, T5 is a thickness of the fifth lens element along theoptical axis, T6 is a thickness of the sixth lens element along theoptical axis and G56 is an air gap between the fifth lens element andthe sixth lens element along the optical axis, and the optical imaginglens satisfies the relationship: (T5+G56+T6)/(T3+T4)≤1.400.
 13. Theoptical imaging lens of claim 8, wherein T5 is a thickness of the fifthlens element along the optical axis, G12 is an air gap between the firstlens element and the second lens element along the optical axis and G23is an air gap between the second lens element and the third lens elementalong the optical axis, and the optical imaging lens satisfies therelationship: (G12+G23)/T5≥3.000.
 14. The optical imaging lens of claim8, wherein Tmin is the smallest thickness of a lens element from thefirst lens element to the sixth lens element along the optical axis andGmax is the largest air gap from the first lens element to the sixthlens element along the optical axis, and the optical imaging lenssatisfies the relationship: Gmax/Tmin≤2.400.
 15. An optical imaginglens, from an object side to an image side in order along an opticalaxis comprising: a first lens element, a second lens element, a thirdlens element, a fourth lens element, a fifth lens element, and a sixthlens element, the first lens element to the sixth lens element eachhaving an object-side surface facing toward the object side and allowingimaging rays to pass through as well as an image-side surface facingtoward the image side and allowing the imaging rays to pass through; anoptical axis region of the object-side surface of the second lenselement is convex; a periphery region of the object-side surface of thethird lens element is convex and an optical axis region of theimage-side surface of the third lens element is concave; a peripheryregion of the object-side surface of the fifth lens element is concaveand an optical axis region of the image-side surface of the fifth lenselement is concave; and an optical axis region of the image-side surfaceof the six lens element is convex; wherein lens elements included by theoptical imaging lens are only the six lens elements described above, AAGis a sum of five air gaps from the first lens element to the sixth lenselement along the optical axis, EFL is an effective focal length of theoptical imaging lens, TTL is a distance from the object-side surface ofthe first lens element to an image plane along the optical axis, BFL isa distance from the image-side surface of the sixth lens element to theimage plane along the optical axis to satisfy the relationships:AAG/EFL≤2.700 and TTL/(EFL+BFL)≥1.800.
 16. The optical imaging lens ofclaim 15, wherein T2 is a thickness of the second lens element along theoptical axis, G12 is an air gap between the first lens element and thesecond lens element along the optical axis and G23 is an air gap betweenthe second lens element and the third lens element along the opticalaxis, and the optical imaging lens satisfies the relationship:EFL/(G12+T2+G23)≤1.400.
 17. The optical imaging lens of claim 15,wherein T3 is a thickness of the third lens element along the opticalaxis and G23 is an air gap between the second lens element and the thirdlens element along the optical axis, and the optical imaging lenssatisfies the relationship: AAG/(G23+T3)≤1.400.
 18. The optical imaginglens of claim 15, wherein υ3 is an Abbe number of the third lenselement, υ4 is an Abbe number of the fourth lens element and υ5 is anAbbe number of the fifth lens element, and the optical imaging lenssatisfies the relationship: υ3+υ4+υ5≤120.000.
 19. The optical imaginglens of claim 15, wherein T2 is a thickness of the second lens elementalong the optical axis, G12 is an air gap between the first lens elementand the second lens element along the optical axis, G34 is an air gapbetween the third lens element and the fourth lens element along theoptical axis and G45 is an air gap between the fourth lens element andthe fifth lens element along the optical axis, and the optical imaginglens satisfies the relationship: (G12+G34+G45)/T2≤2.200.
 20. The opticalimaging lens of claim 15, wherein T1 is a thickness of the first lenselement along the optical axis, T3 is a thickness of the third lenselement along the optical axis, T4 is a thickness of the fourth lenselement along the optical axis and G34 is an air gap between the thirdlens element and the fourth lens element along the optical axis, and theoptical imaging lens satisfies the relationship: (T3+G34)/(T1+T4)≤1.000.